Along with the increase of vehicles on the roads, the traffic control at intersections becomes more and more important. Data released by the Ministry of Public Security in 2010 showed that, traffic accidents at the intersections, e.g., three-way or four-way intersections, accounted for 19% of the total traffic accidents.
Generally, a traffic light control system is provided at the intersection so as to control the traffic there. However, for the conventional traffic light control system, a large number of facilities need to be provided on ground. Due to the high facility cost and the maintenance cost, the traffic light control systems are merely widely provided for urban roads, and they are not widely provided for rural roads or intercity roads. In the case that the traffic light control system is not provided at the intersection, there will be a relatively high risk of traffic accidents.
In a word, there is a relatively high risk of traffic accidents at the intersection without any traffic light control system.